Legal claims defining the scope of protection. Each claim is shown in both the original legal language and a plain English translation.
1. A demodulator, comprising: a register configured to store a phase calibration value having an integer part and a fractional part; a noise-shaping modulator configured to generate a succession of quantized values of integer type, the quantized values having a mean equal to the phase calibration value; a generation stage configured to generate a demodulating signal phase locked with an input signal modulated in-phase and quadrature, the demodulating signal having a phase which depends linearly on the quantized values; and a demodulation stage configured to demodulate the input signal through the demodulating signal.
This invention relates to digital signal processing, specifically to demodulation of signals modulated in-phase and quadrature (I/Q). The problem addressed is the accurate demodulation of such signals, particularly in the presence of phase inaccuracies. The disclosed demodulator includes a register that stores a phase calibration value. This value is composed of an integer part and a fractional part. A noise-shaping modulator receives this phase calibration value and generates a sequence of integer-type quantized values. The key characteristic of these quantized values is that their average value is equal to the stored phase calibration value. A generation stage utilizes these quantized values to produce a demodulating signal. This demodulating signal is designed to be phase-locked with the incoming I/Q modulated input signal. Crucially, the phase of the demodulating signal changes linearly in proportion to the generated quantized values. Finally, a demodulation stage employs this phase-locked demodulating signal to demodulate the input signal. This process effectively extracts the original information from the I/Q modulated signal by aligning the demodulating signal's phase with the input signal's phase, thereby compensating for potential phase errors through the noise-shaping and linear phase dependency.
2. The demodulator according to claim 1 wherein the noise-shaping modulator comprises a sigma-delta modulator.
This invention relates to signal demodulation, specifically addressing the problem of accurately recovering a desired signal from a noisy or distorted input. The core of the invention is a demodulator designed to process an input signal. This demodulator incorporates a noise-shaping modulator. The noise-shaping modulator's function is to shape the noise spectrum of the signal, pushing the noise to frequencies where it is less likely to interfere with the desired signal. In a preferred embodiment, this noise-shaping modulator is implemented as a sigma-delta modulator. A sigma-delta modulator is a type of analog-to-digital converter that uses oversampling and noise shaping to achieve high resolution. By employing a sigma-delta modulator within the demodulator, the system can effectively reduce the impact of noise on the demodulated output, leading to a cleaner and more accurate representation of the original signal. This is particularly beneficial in applications where signal integrity is critical and noise can degrade performance.
3. The demodulator according to claim 2 , wherein the input signal has a first frequency and wherein the generation stage is configured to receive a clock signal phase locked with the input signal and having a second frequency equal to an integer multiple of the first frequency, and wherein the phase of the demodulating signal depends on the quantized values through a coefficient which is directly proportional to the ratio between the first and second frequencies.
This invention relates to signal processing, specifically to demodulators for extracting information from modulated signals. The problem addressed is the efficient and accurate demodulation of input signals, particularly when dealing with frequency relationships between the input signal and a clock signal. The demodulator includes a generation stage. This stage is configured to receive an input signal having a first frequency. It also receives a clock signal that is phase-locked with the input signal. The clock signal has a second frequency, which is an integer multiple of the first frequency. The generation stage produces a demodulating signal. The phase of this demodulating signal is determined by quantized values. This determination is made through a coefficient. This coefficient is directly proportional to the ratio between the first frequency of the input signal and the second frequency of the clock signal. This configuration allows for precise phase control of the demodulating signal, enabling accurate extraction of information from the input signal.
4. The demodulator according to claim 3 wherein the noise-shaping modulator is configured to generate the succession of quantized values with a frequency equal to the first frequency or twice the first frequency.
A demodulator system includes a noise-shaping modulator that processes an input signal to generate a succession of quantized values. The noise-shaping modulator is configured to produce these quantized values at a frequency equal to a first frequency or twice the first frequency. The first frequency is typically the sampling frequency of the input signal or a related frequency used in the demodulation process. The noise-shaping modulator reduces quantization noise in the output signal by shaping the noise spectrum, ensuring that the noise is pushed to frequencies where it is less perceptible or can be more easily filtered out. The demodulator may also include a digital filter that processes the quantized values to further refine the output signal, removing unwanted noise and distortion. The system is particularly useful in applications requiring high-precision signal demodulation, such as in communication systems, audio processing, or sensor signal conditioning, where minimizing quantization noise is critical for accurate signal recovery. The noise-shaping modulator's ability to operate at either the first frequency or twice the first frequency provides flexibility in system design, allowing optimization for different performance and power consumption requirements.
5. The demodulator of claim 1 , wherein the demodulating signal is a square wave signal.
A demodulator for processing a received signal. The demodulator includes a mixer, a low-pass filter, and a detector. The mixer is configured to receive the received signal and a demodulating signal. The low-pass filter is configured to receive an output from the mixer and filter out high-frequency components. The detector is configured to receive an output from the low-pass filter and generate a demodulated signal. The demodulating signal is a square wave signal. This configuration allows for efficient extraction of information from a modulated carrier wave by mixing it with a square wave, filtering out unwanted frequencies, and then detecting the resulting signal. The use of a square wave as the demodulating signal simplifies the mixing process and can lead to a more robust demodulation in certain applications.
6. The demodulator of claim 1 , wherein the demodulator stage comprises: a multiplier circuit configured to multiply the input signal and the demodulating signal to generate a product signal; and a filter coupled to the multiplier circuit to receive the product signal and configured to filter the product signal to generate the and includes receive the input signal and having an output coupled to a high pass filter configured to generate a demodulated signal.
This invention relates to a demodulator circuit designed for extracting a demodulated signal from an input signal. The problem addressed is the need for an efficient and accurate demodulation process, particularly in systems where signal integrity and noise reduction are critical. The demodulator includes a multiplier circuit that receives an input signal and a demodulating signal, multiplying them to produce a product signal. This product signal is then fed into a filter, which processes it to generate the demodulated output. The filter is specifically configured to remove unwanted frequency components, ensuring the output signal is clean and accurate. Additionally, the demodulator may include a high-pass filter to further refine the demodulated signal by attenuating low-frequency noise or interference. The demodulator is particularly useful in communication systems, signal processing applications, and any scenario where precise demodulation of modulated signals is required. The use of a multiplier followed by a filter ensures that the demodulated signal retains its integrity while minimizing distortion and noise. The high-pass filter stage further enhances signal quality by removing unwanted low-frequency components, making the demodulator suitable for high-performance applications.
7. A control and sensing circuit for a MEMS gyroscope, comprising: a demodulator including, a register configured to store a phase calibration value having an integer part and a fractional part; a noise-shaping modulator configured to generate a succession of quantized values of integer type, the quantized values having a mean equal to the phase calibration value; a generation circuit configured to generate a demodulating signal phase locked with an input signal modulated in-phase and quadrature, the demodulating signal having a phase which depends linearly on the quantized values; and a demodulation circuit configured to demodulate the input signal through the demodulating signal; and a driving circuit configured to be coupled to an oscillating system that generates the input signal, the driving circuit configured to generate a clock signal and to provide the oscillating system with a driving signal having a first frequency.
This invention relates to control and sensing circuits for Micro-Electro-Mechanical Systems (MEMS) gyroscopes. The problem addressed is the accurate demodulation of signals from a MEMS gyroscope, particularly in the presence of noise and the need for precise phase calibration. The circuit includes a demodulator. This demodulator contains a register for storing a phase calibration value, which has both an integer and a fractional component. A noise-shaping modulator generates a series of quantized integer values. The average of these quantized values is designed to match the stored phase calibration value. A generation circuit creates a demodulating signal. This signal is phase-locked with an input signal that is modulated in both its in-phase and quadrature components. The phase of this demodulating signal is directly influenced by the quantized values. A demodulation circuit then uses this demodulating signal to process the input signal. Additionally, a driving circuit is provided. This circuit connects to an oscillating system that produces the input signal. The driving circuit generates a clock signal and supplies a driving signal to the oscillating system. This driving signal has a specific first frequency, which is crucial for the operation of the MEMS gyroscope's oscillating system.
8. The control and sense circuit according to claim 7 , wherein the demodulator and the driving circuit are formed in a main die.
This invention relates to electronic circuits for controlling and sensing operations, specifically addressing the integration of components for improved efficiency and performance. The problem solved is the need for a compact and integrated solution for demodulation and driving functions within a control and sense circuit. The control and sense circuit includes a demodulator and a driving circuit. The demodulator is configured to process a received signal, extracting relevant information. The driving circuit is coupled to the demodulator and is responsible for generating control signals based on the demodulated information. These control signals are then used to operate or influence an external system or component. In a specific embodiment, the demodulator and the driving circuit are fabricated on a single main semiconductor die. This integration minimizes the physical footprint of the circuit, reduces parasitic effects between the components, and can lead to lower manufacturing costs and improved signal integrity. The main die serves as the substrate for both the demodulator and the driving circuit, allowing for direct electrical connections between them and potentially shared power and ground lines. This arrangement is particularly beneficial in applications where space is limited or high-speed operation is required.
9. The control and sense circuit according to claim 8 , wherein the input signal is received from the oscillating system that is formed in a second die separate from the main die.
This invention relates to integrated circuit design and addresses the challenge of managing signal integrity and power delivery in complex multi-die systems. Specifically, it concerns a control and sense circuit designed to operate with an oscillating system. The core of the invention is a control and sense circuit. This circuit is configured to receive an input signal. A key aspect of this embodiment is that the input signal originates from an oscillating system. This oscillating system is not integrated onto the same semiconductor die as the control and sense circuit. Instead, the oscillating system is fabricated on a second, separate die. This separation implies a multi-die or chiplet architecture where different functional blocks are placed on distinct semiconductor substrates. The control and sense circuit then processes or monitors this input signal, likely for purposes of synchronization, timing, or performance monitoring within the overall system. The separation of the oscillating system onto a second die suggests a design choice aimed at optimizing factors such as thermal management, signal isolation, or manufacturing flexibility for different components.
10. The control and sense circuit according to claim 7 , wherein the noise-shaping modulator is a sigma-delta modulator.
This invention relates to electronic circuits for controlling and sensing signals, specifically addressing the problem of improving signal quality by reducing noise. The core of the invention is a control and sense circuit that incorporates a noise-shaping modulator. This modulator is designed to shape the noise spectrum of a signal, pushing the noise to higher frequencies where it can be more easily filtered out or is less detrimental. In a preferred embodiment, the noise-shaping modulator is implemented as a sigma-delta modulator. A sigma-delta modulator is a type of analog-to-digital converter (ADC) that uses oversampling and noise shaping to achieve high resolution. It quantifies an analog signal by comparing it to a reference voltage and generating a stream of digital bits. The noise shaping process within the sigma-delta modulator effectively reduces the in-band noise, thereby improving the signal-to-noise ratio (SNR) of the sensed signal. This enhanced signal quality is then utilized by the control circuitry for more accurate and reliable operation.
11. The demodulator according to claim 7 , wherein the driving circuit includes a phase-locked loop configured to generate a clock signal that is phase locked with the input signal and having a second frequency equal to an integer multiple of the first frequency, the clock signal being applied to the generation circuit.
This invention relates to electronic signal processing, specifically to demodulators for recovering information from modulated signals. The problem addressed is the accurate generation of a clock signal for use in a demodulator, ensuring proper synchronization with the incoming signal. The demodulator incorporates a driving circuit that includes a phase-locked loop (PLL). This PLL is designed to generate a clock signal. The key feature of this clock signal is that it is phase-locked with the input signal, meaning its phase is synchronized. Furthermore, the clock signal has a second frequency that is an integer multiple of a first frequency. This synchronized, frequency-multiplied clock signal is then supplied to a generation circuit within the demodulator. This ensures that subsequent signal processing steps, such as data recovery or symbol detection, are performed at the correct timing relative to the incoming modulated signal, thereby improving demodulation accuracy.
12. The demodulator according to claim 11 , wherein the phase of the demodulating signal depends on the quantized values through a coefficient which is directly proportional to a ratio of the first and second frequencies.
This invention relates to digital signal processing, specifically to demodulation of signals. The problem addressed is the accurate demodulation of signals where the phase of the demodulating signal needs to be precisely controlled based on signal characteristics. The system includes a demodulator that processes an input signal. A key aspect is the generation of a demodulating signal. The phase of this demodulating signal is determined by quantized values derived from the input signal. This phase dependency is established through a coefficient. This coefficient is directly proportional to the ratio of a first frequency and a second frequency. The first frequency is related to the input signal, and the second frequency is a reference or carrier frequency. By making the coefficient dependent on this frequency ratio, the demodulator can adapt its phase adjustment to variations in the input signal's frequency relative to the reference, thereby improving demodulation accuracy. This allows for robust demodulation even when the input signal's frequency deviates from the ideal.
13. The demodulator according to claim 12 , wherein the noise-shaping modulator is configured to generate the succession of quantized values with a frequency equal to the first frequency or twice the first frequency.
This invention relates to signal processing, specifically to demodulators used in communication systems. The problem addressed is the efficient and accurate recovery of a desired signal from a noisy input. The system includes a demodulator that processes an input signal. A key component is a noise-shaping modulator. This modulator is designed to generate a sequence of quantized values. The quantization process inherently introduces errors, and noise shaping is a technique used to manipulate the spectral distribution of this quantization noise, pushing it to frequencies where it is less likely to interfere with the desired signal. The specific configuration of the noise-shaping modulator is that it generates this succession of quantized values at a particular frequency. This generation frequency is either equal to a defined "first frequency" or twice that "first frequency." This controlled generation frequency is crucial for effectively shaping the quantization noise and ensuring it does not corrupt the demodulated output signal. The demodulator then utilizes these shaped quantized values to reconstruct the original information carried by the input signal.
14. A MEMS gyroscope, comprising: a control and sense circuit including: a demodulator including, a register configured to store a phase calibration value having an integer part and a fractional part; a noise-shaping modulator configured to generate a succession of quantized values of integer type, the quantized values having a mean equal to the phase calibration value; a generation circuit configured to generate a demodulating signal phase locked with an input signal modulated in-phase and quadrature, the demodulating signal having a phase which depends linearly on the quantized values; and a demodulation circuit configured to demodulate the input signal through the demodulating signal; and a driving circuit configured to receive the input signal, the driving circuit configured to generate a clock signal and to provide the oscillating system with a driving signal having a first frequency; and oscillating system coupled to the driving circuit and configured to generate the input signal, the input signal being indicative of an angular velocity experienced by the MEMS gyroscope.
MEMS Gyroscopes. This invention addresses the accurate measurement of angular velocity in Micro-Electro-Mechanical Systems (MEMS) gyroscopes. It describes a MEMS gyroscope system that utilizes a sophisticated control and sense circuit for improved demodulation and signal processing. The system includes a control and sense circuit. Within this circuit, a demodulator is present. The demodulator contains a register for storing a phase calibration value, which has both an integer and a fractional component. A noise-shaping modulator generates a series of integer-type quantized values. These quantized values are designed to have a mean that matches the stored phase calibration value. A generation circuit creates a demodulating signal. This signal is phase-locked with an input signal that is modulated in both in-phase and quadrature components. The phase of this demodulating signal is directly proportional to the quantized values. A demodulation circuit then uses this demodulating signal to process the input signal. Additionally, a driving circuit receives the input signal. It generates a clock signal and provides an oscillating system with a driving signal at a specific frequency. The oscillating system, connected to the driving circuit, generates the input signal. This input signal is ultimately representative of the angular velocity detected by the MEMS gyroscope.
15. The MEMS gyroscope according to claim 14 , wherein said the demodulator and driving circuit are formed in a first die and the oscillating system is formed in a secondary die.
This invention relates to micro-electromechanical systems (MEMS) and specifically to MEMS gyroscopes. The problem addressed is the efficient and integrated fabrication of MEMS gyroscopes. The MEMS gyroscope comprises an oscillating system and a demodulator and driving circuit. The oscillating system is responsible for generating and maintaining mechanical oscillations that are sensitive to angular velocity. The demodulator and driving circuit are configured to process the signals from the oscillating system to determine the angular velocity. A key aspect of this gyroscope is its fabrication approach. The demodulator and driving circuit are integrated onto a first semiconductor die. Separately, the oscillating system, which is the core sensing element of the gyroscope, is fabricated on a secondary semiconductor die. This separation allows for optimized fabrication processes for each component, potentially leading to improved performance, yield, or cost-effectiveness. The two dies are then assembled to form the complete MEMS gyroscope.
16. A method for demodulating an in-phase component of an input signal that is in-phase and quadrature modulated, the method comprising: storing a phase calibration value having an integer part and a fractional part; generating a succession of quantized values of integer type, the quantized values having a mean equal to the phase calibration value; generating a demodulating signal phase locked with the input signal, the demodulating signal having a phase which depends linearly on the quantized values; and demodulating the input signal by means of the demodulating signal.
This invention relates to digital signal processing, specifically to the demodulation of in-phase and quadrature (I/Q) modulated signals. The problem addressed is the accurate demodulation of the in-phase component of such signals, which can be affected by phase inaccuracies. The method involves storing a phase calibration value that includes both an integer and a fractional part. A series of integer-type quantized values are then generated. These quantized values are designed to have a mean that matches the stored phase calibration value. Concurrently, a demodulating signal is generated. This demodulating signal is phase-locked with the incoming I/Q modulated signal. Crucially, the phase of this demodulating signal is determined by a linear relationship with the generated quantized values. Finally, the in-phase component of the input signal is demodulated using this phase-locked demodulating signal. This process effectively corrects for phase errors by using a calibrated and dynamically adjusted demodulating signal.
17. The demodulation method according to claim 16 wherein the input signal has a first frequency, wherein the method further comprises: generating a clock signal phase locked with the input signal and having a second frequency that is equal to an integer multiple of the first frequency; and wherein generating the demodulating signal includes generating the demodulating signal on the basis of the clock signal with the phase being a function of the quantized values through a coefficient that is directly proportional to a ratio between the first and second frequencies.
This invention relates to signal demodulation techniques, specifically for extracting information from input signals with precise phase tracking. The problem addressed is the need for accurate demodulation of signals where phase alignment and frequency synchronization are critical, such as in communication systems or sensor applications. The method involves processing an input signal with a first frequency. A clock signal is generated that is phase-locked to the input signal but operates at a second frequency, which is an integer multiple of the first frequency. This clock signal ensures precise timing alignment with the input signal. The demodulating signal is then generated based on this clock signal, where its phase is adjusted as a function of quantized values derived from the input signal. The adjustment uses a coefficient that scales proportionally to the ratio between the first and second frequencies, ensuring accurate phase tracking across different frequency relationships. This approach improves demodulation accuracy by maintaining phase coherence through frequency multiplication and adaptive phase correction, reducing errors in signal recovery. The technique is particularly useful in systems requiring high-fidelity demodulation, such as digital communication receivers or phase-sensitive measurement devices. The use of integer frequency multiplication simplifies implementation while maintaining precise phase alignment.
18. The method of claim 16 , wherein generating the succession of quantized values comprises generating the succession of quantized through noise-shaping modulation.
This invention relates to signal processing, specifically to methods for generating a succession of quantized values. The problem addressed is the efficient and accurate representation of analog signals in a digital domain, particularly in systems where quantization noise can degrade signal quality. The method involves generating a succession of quantized values. This generation process is characterized by the specific technique used for quantization. In one embodiment, the succession of quantized values is generated through noise-shaping modulation. Noise-shaping modulation is a technique that manipulates the quantization error, pushing it to higher frequencies where it can be more easily filtered out or is less perceptible, thereby improving the signal-to-noise ratio in the desired frequency band. This approach is particularly useful in digital-to-analog conversion or in the digitization of analog signals where minimizing audible or perceptible noise is critical.
19. The method of claim 18 , wherein generating the succession of quantized values through noise-shaping modulation comprises generating the succession of quantized values through sigma-delta modulation.
Audio signal processing. This invention addresses the problem of efficiently and accurately converting a continuous analog audio signal into a digital representation, particularly for applications requiring high fidelity and reduced quantization noise. The method involves generating a succession of quantized digital values from an analog input signal. This generation process is achieved through a specific type of modulation known as noise-shaping modulation. Noise-shaping modulation is a technique used to push quantization noise to higher frequencies, away from the audible range, thereby improving the perceived signal-to-noise ratio. Specifically, the noise-shaping modulation employed is sigma-delta modulation. Sigma-delta modulation is a widely used oversampling analog-to-digital conversion technique that utilizes feedback and a low-resolution quantizer to achieve high resolution. The process involves oversampling the analog signal at a rate significantly higher than the Nyquist rate and then quantizing the oversampled signal with a simple quantizer (e.g., a 1-bit quantizer). A feedback loop then subtracts the quantized output from the oversampled input, and this difference signal is integrated and then quantized again. This feedback mechanism shapes the noise spectrum, concentrating quantization noise at higher frequencies, which can then be filtered out by a digital low-pass filter to recover the original signal with high accuracy.
20. A method, comprising: performing a calibration of a MEMS gyroscope that includes arranging the MEMS gyroscope in a way in which it experiences a known or zero angular velocity; for each value of a plurality of test values, each test value having an integer part and a fractional part, the method including: storing the test value; generating through a noise-shaping modulator a succession of quantized values of the integer type, quantized values having a mean equal to the test value; generating a corresponding demodulating signal phase locked with a sense signal generated by the MEMS gyroscope when experiencing the known or zero angular velocity, the demodulating signal having a phase which depends linearly on the quantized values; and through the corresponding demodulating signal, demodulating a sense signal generated by the MEMS gyroscope to generate a corresponding base band signal; selecting the test value that provides the corresponding base band signal having the smallest quadrature error; and storing the selected test value.
MEMS Gyroscope Calibration and Signal Processing This invention relates to improving the accuracy of Micro-Electro-Mechanical Systems (MEMS) gyroscopes by refining their calibration process and signal demodulation. MEMS gyroscopes are susceptible to errors, particularly quadrature error, which can degrade the precision of angular velocity measurements. The method involves calibrating a MEMS gyroscope by orienting it to experience a known or zero angular velocity. During this calibration, a series of test values, each with an integer and fractional part, are stored. For each stored test value, a noise-shaping modulator generates a sequence of integer-type quantized values whose average matches the test value. Simultaneously, a demodulating signal is generated. This demodulating signal is phase-locked with the sense signal produced by the gyroscope under the known or zero angular velocity condition. Crucially, the phase of this demodulating signal varies linearly with the quantized values. This phase-locked demodulating signal is then used to demodulate the gyroscope's sense signal, producing a baseband signal. The method identifies and stores the specific test value that results in a baseband signal exhibiting the minimum quadrature error. This selected test value represents an optimized calibration parameter for the gyroscope.
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May 12, 2020
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